The team takes desperate action in its race to prevent Samaritan from coming online and making them its first targets. Meanwhile, the months-long battle with the anti-surveillance terrorist group Vigilance comes to a shocking conclusion.

Danger closes in when the epic battle to bring the criminal organization HR to justice reaches new heights. And when the Machine suddenly gives out Reese's number, the POI team faces their greatest threat yet.

As Reese and Shaw race to catch up with Finch, he infiltrates a maximum-security government facility in a desperate mission which could mean the end for not only Samaritan, but for himself and The Machine as well.

During the helicopter ride to the ship, Desmond's consciousness begins jumping back and forth between present day 2004 and 1996. He is forced to find Daniel Faraday in 1996 in order to get answers and stop the jumps.

Jack and the survivors wait for Charlie to turn off The Others' signal-jamming device, not knowing that he has been captured at the Looking Glass station. In addition, Sayid, Jin and Bernard are captured after The Others invade the camp.

It's been ten days since the machine has provided a number, which means Carter has had ten days of dead bodies piling up. Finch discovers that a company called Decima is responsible for the... See full summary »

(Part II of II) The castaways on the raft are surprised at sea by something unexpected. Meanwhile, remaining islanders attempt to blow open the hatch, and a visitor to the encampment might be a threat to Claire's infant son.

After discovering a sailboat just offshore containing former hatch oversee Desmond, Jack and Sayid come up with a plan to confront "The Others" and hopefully get Walt back. Meanwhile, Eko and Locke come to blows as Locke makes a potentially cataclysmic decision regarding the "button" and the hatch.

The mysterious criminal mastermind known as "The Voice" returns and traps Reese and Fusco in their own precinct with several armed gang members and the latest POI. Also, Root makes a shocking discovery.

Ben tries to escape Keamy's custody so that he and Locke can follow through with Jacob's request to move the island. Michael tries to neutralize the explosives on the boat, while the "Oceanic 6" move closer to rescue.

Decima has completed its beta test of Samaritan and has now shut it down temporarily as Greer has to get the politicos, namely Garrison, to buy into the need to purchase it in the name of ... See full summary »

The mysteries behind Richard Alpert's arrival to the island, his immortality, and his alliance with Jacob are revealed--plus more details about the purpose of the island and the relationship between Jacob and the smoke monster.

Finch, Shaw and Arthur Claypool are able to escape from the clutches of Control, after which Arthur demonstrates that he has more lucid moments than he initially lets on. He informs Finch ... See full summary »

As Donnelly escorts Carter and Reese to their incarceration, they are ambushed, their attacker who kills Donnelly and abducts Reese. That attacker is Reese's old and supposedly deceased ... See full summary »

News of Northern Lights has hit the media, meaning that the team's work has become more difficult if only because of the public eye on what is happening. While Shaw heads off with Root on ... See full summary »

Flashbacks to Finch's adolescence provide insight into his creation of The Machine. Also, the team receives the number of an already dying man, and Reese leaves the POI team behind in the aftermath of the war with the crime organization.

Walter flashes back to 1985 while explaining Peter's otherworldly origins to Olivia. Also, Peter's mother is introduced, and details of the neighboring world reaffirms that there is more than one of everything.

Forty-eight survivors of an airline flight originating from Australia, bound for the U.S., which crash-lands onto an unknown island 1000 miles off course, struggle to figure out a way to survive while trying to find a way to be rescued.

On Election Day Reese shoots a potential jumper and is forced to go into counseling. The new number is for a pollster who suspects the election for Governor of New York was rigged. It was - by Samaritan, and his life is now in danger.

Jack and Sayid's plan faces resistance from Sawyer, Juliet, and Kate. Ben and The Others/Hostiles reach Jacob at the Foot of the Statue, and are soon met by the 316 survivors, who reveal the contents of their mysterious package.